Very rare and hard to find replacement click spring for the clockworks of Allgaier from Germany. There are 2 versions possible. The version with smaller core is sold as model 1 in our store. Allgaier Bros. from Schönwald build this clockwork with a totally different click spring method then the regular gravity clockworks. They are custom made for us. Click spring may need adjustments when placed on the gear, after all they are not factory made but hand cut with laser.